Hi i had one of these if i recal the needle setting was like in the 1 turns setting all you need to have is a trail of smoke coming from the pipe and you will be fine as long as you see a nice trail of smoke your motor should be fine...... A temp gun is good don't go over 250deg...
Also about it driving crooked that's the nature of the blizzard you can try tightening and adjusting the drive chains... and also try swaping the tracks to the oposite side.

Good luck.
Shen